One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(6,8)(9,10)(11,17)(12,19)(13,16)(14,15)(18,24)(20,21)(22,23)(25,26,32,35)(27,36,30,33)(28,31,29,34)(37,38,39,40)(10,15)(12,17)(16,23)(20,24)(25,27,32,30)(26,33,35,36)(28,39,29,37)(31,38,34,40)(1,2,5,4)(3,6,7,8)(25,28,32,29)(26,34,35,31)(27,37,30,39)(33,38,36,40)(3,7)(6,8)(9,11,14,19)(10,12,15,17)(13,21,22,18)(16,24,23,20)(25,29,32,28)(26,31,35,34)(27,37,30,39)(33,38,36,40)(1,3,5,7)(2,6,4,8)(9,12)(10,11)(13,20)(14,17)(15,19)(16,18)(21,23)(22,24)(25,30,32,27)(26,33,35,36)(28,39,29,37)(31,40,34,38)(1,4,5,2)(3,8,7,6)(9,13,14,22)(10,16,15,23)(11,18,19,21)(12,20,17,24)(25,31)(26,28)(27,38)(29,35)(30,40)(32,34)(33,39)(36,37)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.